This is a competing continuation application. This longitudinal study examines the etiologic determinants of changes between adolescence and adulthood in alcohol and drug use and dependence, and the consequences of alcohol and drug use and abuse/dependence on the individual's functioning. The ultimate goal of this research is to investigate developmental pathways to alcohol and drug use and dependence and cessation, and to identify adult protective factors that will offset risks for alcohol and drug use and dependence in adulthood. The sample includes low-income urban African American and Puerto Rican adults who were seen in early/middle adolescence, then in late adolescence, then in their early 20's, and again in their mid 20's. We now propose to study them in their thirties. A fifth data collection is proposed to accomplish the following: (1) examine the interrelations and interactions of risk and protective factors, including personality, family, peers, ecological context, acculturation/cultural values, and African American and Puerto Rican ethnic/racial identity, as they affect the course of alcohol and drug use/abuse/dependence (i.e., onset, stability, cessation) and criminal behavior in these adults; and (2) To study the consequences of early alcohol and drug use and abuse/dependence and other problem behaviors on adult intra- and interpersonal functioning. Interviews with the adult participants will be conducted by trained, interviewers. Scales with adequate psychometric properties measuring the independent variables will be developed from the interview schedules. The primary analytic techniques will be structural equation modeling and other regression-based techniques. This research will enable us to provide further information on (1) suggested specific strategies to prevent increases in alcohol and drug use and dependence, (2) factors promoting the decrease or cessation of drug use, and (3) the timing most adequate to implement these strategies.